Gellan-based Systems for Sustained Ophthalmic Delivery of Ofloxacin

It is common knowledge that the ocular bioavailability and therapeutic response of drugs applied topically as eye drops is very poor, this is due to rapid precorneal drainage of the instilled dose, which could be overcome by the use of in-situ gelling systems that undergo a sol-gel transition in the cul-de-sac. This work describes the ophthalmic formulation of an antibacterial agent ofloxacin, based on the concept of ion-activated in-situ gelation by using the polymer Gellan gum, a novel vehicle for sol-gel transition, which gels in the presence of mono/divalent cations present in the tear fluid. The formulations were characterized for in vitro drug release and rheological properties. The physical stability and interaction between the exipients of the selected formulations were determined following steam sterilization and storage at 25oC and 40oC. The optimized formulations were therapeutically efficacious and demonstrate to possess consistency that is favorable to prolong the drug release properties over an extended period of time (12 h). The physical stability, following steam sterilization and storage, the optimum viscosity combined with sustained release of the drug make the formulations “C” and “C-Beta” the promising formulations as an alternative to conventional eye drops.